Electrically-adjustable propeller



Feb, 18, 1930. 1-. DUPREY ELECTRICALLY ADJUSTABLE PROPELLER Filed Aug.3, 1927 .3 Sheets-Sheet I/VVf/V TOR.

Tho/ms DUPREY ITTORIVEY.

I 18, 1930. DUPREY 1,747,230

ELECTRICALLY ADJUSTABLE PROPELLER INVEN T 0 R THO/M5 1714mm.

ATTDPHFY Feb. 18, l 930. DUPREY 1,747,230

ELECTRICALLY ADJUSTABLE PROPELLER Filed Aug. 3, 1927 v"5 Sheets-Sheet 37" i i fa INVENTOR. Two/ms DuPnEy.

Patented Feb. 18, 1930 UNITED STATES THOMAS DUPBEY, LONG BEACH,GALIEORNTA ELEGTRICALLY-ADJUSTAIBLE PROPELLEE Application filed Augusta, 1927. Serial No. 210,327.

An object of my invention is-to provide a power actuated means foradjusting the blades of an airplane propeller.

Another obj ect-is to so position and arrange the actuating motor thatit will not be infiuenced b the centrifugal force of the rotating propeler.

btill another object is to provide an adjustable propeller which may beinstalled without disturbing or rearranging the general structure of theplane. I

An advantage of my invention resides in the simplicity of the drivebetween the motor and the blades, and in the few parts required in theoperation of my device.

Otherobjects, advantages, and features of invention may appear from theaccompanying drawing, the subjoined detailed description, andiheappended claims.

In the drawing- Fig. 1 is a fragmentary side elevation of myelectrically adjustable propeller.

Fig. 2 is an end view of the same.

Fig. 3 is a transverse sectional view of my propeller.

Fig. 4 is a fragmentary longitudinal sectional view of my propeller. V

Fig. 5 is a view similar to Fig. 4 but showing the drive gears.

Fig. 6 is a side elevation of the adjustable screw and traveller.

Fig. 7 is a rear view of the adjustment indicator.

Fig. 8 is a transverse sectional view of the same.

Fig. 9 is a wiring diagram illustrating the method of operatingmy'propeller.

Referring more particularly to the draw- My propeller comprises a pairof blades 1,

2 which blades are adjustably mounted in a hollow hub 3, in a manner tobe further described. The hollow hub 3 comprises bearings 4, 5 in whichthe shanks 6, 7 'of the blades 1, 2, respectively, are journaled. Acentral operating compartment 8 is formed in the hub 3 between thebearings 4, 5 and the drive shaft 9 of the motor is secured in thecentral section as follows: A sleeve 16 is securely bolted, or

60 otherwise secured, to the rear face of the section 8, and this sleevefits into a socket 11 which is bolted, or otherwise secured, against thefront face of the sectionj8. The drive shaft of the motor is suitablykeyed,.or otherwise secured, in the sleeve 10 and socket 11 whereby thepropeller isrotated.

In either side of the sleeve 10 and within the central section 8, Ijournal a pair of adjusting screws 12, 13. To the forward ends of thescrews 12, 13 are secured gears 14, 15, respectively, which gears areenclosed in a. housing 16 on which housing the electric motor 17 ismounted. A pinion 18 is mounted on the armature shaft of the motor andmeshes with the gears 14, 15, thus simultaneously rotating said gearswhen the motor is operated. The motor is adapted to be rotated bothforwardly and reverse through suitable controlswitches as will befurther described.

Each. of the adjusting screws 12, 13 are threaded through a traveller19, 20 and this traveller is adapted to move back and forth over thelength of the screw as the screw is rotated through the action of thepinion 18 and the gears 14, 15. The travellers 19, 20 are each formedwith a vertical slot 21, 22, respectively, in which a block 23 or 24 isadapted to slide. To the ends of the blade shanks 6, 7 is securelybolted, or otherwise secured, an arm 25, 26, respectively, which armsare positioned within the central section 8 and adjacent the screws 12,13.

The arms 25, 26 are each provided with a pin 27 which extends into theblock 23 or and is journaled in said block. Thus it W111 be seen that asthe travellers 19, 20 move back and forth along the screws 12, 13 thearms 25, 26 will be swung, thus rotating the shank 6, 7 and the blades1, 2 to properly adjust the blades to the required pitch.

Since themotor 17 rotates with the propellers 1, 2 the current supplyingthe motor is fed thereto through movable contact rings 28 and stationarycontact rings 29 hearing against them. The movable rings 28 arepositioned in a housing secured to the central section 8 and thestationary rings are secured to the engine casting, or other suitablestationarypart of the plane. The contact rings 28 comprise an outerindicator ring 30, a for- 1 as stated and as is shown in Fig. 9. Thein-' dicator ring is connected toa point contact switch 38 on the screw12, which switch makes contact on each revolution of the screw. The ring30 is then connected through lead 39 to a dash indicator 40 upon whichis shown the amount of pitch of the blades.

It is obvious that when flying the operator 7 could not accuratelydetermine the pitch of the blades without some indicating. means infront of him. My indicator comprises a housing 41 in which is positioneda dial '42 calibrated to indicate the pitch of the blades. A shaft 43 isjournalled in the housing and a pointer 44 is secured to the shaft andtravels over the dial 42.. A disc 45 is secured to the shaft 43', theouter portion of which disc is formed of metal and "the inner portionsurrounding the shaft is of some suitable insulating material.

A pair of plates 46, 47 are j ournaled on the shaft 43 rearwardly of thedisc 45 and the sections of the plates surrounding the shaft areinsulated therefrom so that there is no transferring of magnetism fromone plate to another. Mounted on each of the plates 46, 47

is a soft iron core 48 surrounded b a coil 49. A metal bar 50 is securedto the ousing 41 below each of theplates- 46, 47 and an insulated coilspring 51 normally urges the plate 46 or 47 upwardly away from the bar-50 against a stop lug 52. The lead'39 extends to one side of both of thecoils 49, the other end of each coil being connected to one of theswitches 35, 36 through leads 53, 54. p

In operation we will assume that the switch 35 rotates the motor 17 ina'direction to give a forwardly pitch to the blades, and,

therefore, termedthe forward switch; Current is fed through the lead 33from the battery 37 to the ring31 and thence to the motor. This causesthe screw-12 to rotate and at each rotation of the screw the contact 38is. closed 50- tinued rotation of the screw and the spring 51 moves theplate 46 and corresponding core 48 upwardly, and during this upwardmovement the core is deenerglzed since there is no current flowingthrough the coil 49, and. c nsequently there will be no retraction ofthe disc 45. Therefore, as the disc is rotated step by step the finger44 will indicate on the dial pitch is obtained and upon releasing theswitch the contact is broken and the motor 17 ceases to rotate- Aspreviously stated the rotation of the motor 17 will rotate the gears 14,15 and the screws 12, 13, thus moving the travellers 19, 20 and swingingthe arms 25, 26 to rotate the blades the required amount.

Having described my invention, claim: 1. An electrically adjustablepropeller comprising a hub, a blades journaled in said hub, a motorsecured to said hub, a screw journaled in the hub adjacent the inner endof each of the blades, gear means connecting the motor and the screw, atraveller threaded onto the screw, a lever plate secured to the blade,and means cou ling the lever plate and the traveller where y said plateis swung as the traveller moves back and forth along the from the leverplate into said block, whereby the lever plate is swung as the travellermoves back and forth along the screw.

3. An electrically adjustable propeller comprising a hollow hub, bladesjournaled in said hub, a sleeve secured to the hub adapted to receivethe drive shaft of the motor,, an electric motor secured to the frontface of the hub, a threaded screw journaled in the hub adjacent theinner end of each blade, gear means connecting the electric motor andthe screws, a traveller on each screw, said traveller having a slotformed therein, a lever plate secured to the inner .ends of each blade,a block in the slot, and a pin extending-from the lever plate 'into theblock whereby the lever plate is swung to adjust the blades as thetraveller moves along the screw, and contact rings secured to the hub.whereby current is fed to the electric motor.

In testimony whereof, I afiix my signature. THOMAS DUPREY.-

